In the related art, as a bearing for a high-speed rotating body, a radial bearing, which is used to be externally attached to a rotary shaft, is known. As the radial bearing, a radial foil bearing is well known, which includes a thin sheet-shaped top foil which forms a bearing surface, a back foil which elastically supports the top foil, and a cylindrical bearing housing which accommodates the top foil and the back foil. As the back foil of the radial foil bearing, a bump foil, in which a thin sheet is formed in a wave shape, is mainly used.
In general, in the radial foil bearing, in order to prevent the top foil or the bump foil from being detached from the bearing housing, one end (toe portion) of the top foil or the bump foil is directly fixed to the bearing housing or is indirectly fixed thereto via a spacer, using spot welding.
Moreover, in order to perform a mechanical fixation instead of the welding, a structure (for example, refer to Patent Document 1) is also known in which a portion or the entirety of one end of the top foil is bent and raised and the one end is engaged with an engagement groove formed on an outer ring (bearing housing).